When is the last time we've had a good old fashioned rain, arctic front move throw change to big snow? Seems like a long time. It's usually light snow to rain or zr.18z GFS
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Pattern Fail or Fab February 2023 Pattern Thread
- Thread starter Metwannabe
- Start date
Been away. 12z CMC earlier. If we could just beat that SE ridge back just a bit and buckle the flow we would be looking at a big winter storm. It’s just so hard to get every ingredient you need 
J1C1111
Member
Going to be right on the razors edge as always around here.
When is the last time we've had a good old fashioned rain, arctic front move throw change to big snow? Seems like a long time. It's usually light snow to rain or zr.
I thought it was just a classic cold chasing moisture look earlier but looking at vort maps there was actually a good moisture fetch and while it is moving fast it still tries to go neutral/negative and pop a fast moving coastal.
I thought it was just a classic cold chasing moisture look earlier but looking at vort maps there was actually a good moisture fetch and while it is moving fast it still tries to go neutral/negative and pop a fast moving coastal.
It’s just a weird system as is. Moisture from Baja to Bermuda. All part of the same system..
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Downeastnc
Member
Back in Feb 2020 we had a rain turn to snow event over eastern NC for a good 3-5" hit, I remember it raining for several hrs before switching over....
I think this event as currently shown has a lot of parallels to that event. (btw... i think raleigh was slated for 3-5ish and we got 1.5)
Downeastnc
Member
Had a solid 4-5" in my backyard...seems like it was like 45-50 that morning and by midafternoon it had switched over to snow....we lost a inch or two to getting the ground cold enough etc as well, snowed a good hr or two before it accumulated and the roads etc never really got bad.
February 20-21, 2020 - Snow Event
www.weather.gov
Christmas storm 2010. Rain to snow
severestorm
Member
Remember that. The clouds at night ruined it with the insulation. 850's looks slightly better this time. GFS is about to roll again, probably a completely different run again haha Hopefully not.
2020
griteater
Member
Yeah, in absence of a strong, trailing upper low (like Mar 2009), it's quite rare I'd say to see moderate/heavy amounts of rain flip to snow that accumulates moderate to heavily. One big reason is that cold air advection aloft is a subsidence mechanism, while warm air advection aloft is a mechanism for rising motion and precip generation. So you need other mechanisms to offset that cold air advection aloft in order to generate precip. But the Feb 2020 example mentioned is a good one. I distinctly remember pointing out the cold air advection aloft being an issue in precip generation back my way in the western half of NC, but it produced some decent snow in the eastern half.
The other one that has been mentioned that is probably the best comparison to the 18z GFS run is the first of the winter storms in Feb 1989 (02/17/89) shown in the loops below. Long fetch of west to east moisture from New Mexico via west to east moving low amp southern stream wave with cold air pressing south from strong and sprawling high pressure
griteater
Member
I tend to view all of these Op and Ensemble model runs as just scatter shot solutions regardless of the model (Euro/GFS/CMC/UKMet). Don't think we will have any clear idea until the weekend. Could completely disappear. Could be a rain event. But it has to hit just right really in order to produce a wintry event
Downeastnc
Member
Yeah, in absence of a strong, trailing upper low (like Mar 2009), it's quite rare I'd say to see moderate/heavy amounts of rain flip to snow that accumulates moderate to heavily. One big reason is that cold air advection aloft is a subsidence mechanism, while warm air advection aloft is a mechanism for rising motion and precip generation. So you need other mechanisms to offset that cold air advection aloft in order to generate precip. But the Feb 2020 example mentioned is a good one. I distinctly remember pointing out the cold air advection aloft being an issue in precip generation back my way in the western half of NC, but it produced some decent snow in the eastern half.
The other one that has been mentioned that is probably the best comparison to the 18z GFS run is the first of the winter storms in Feb 1989 (02/17/89) shown in the loops below. Long fetch of west to east moisture from New Mexico via west to east moving low amp southern stream wave with cold air pressing south from strong and sprawling high pressure
Man I thought you were talking the other Feb 1989 event, a week after this one, a week that saw temps shoot to the mid 60's and tornados followed by probably the second or third biggest snowfall on my life....Feb 89 was a beast for sure.....
LukeBarrette
im north of 90% of people on here so yeah
Meteorology Student
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Probably not cold enough on this ICON run but then again I’m not sure on how ICON handles CAD.
griteater
Member
Yeah that was a completely different setup aloft...it was a hardcore Manitoba Mauler upper wave / low that dove in from the NW....really good one
severestorm
Member
The reason you're not seeing a pronounced CAD is because the Dominant High is still in Central Canada and the Low is still departing New England. I suspect there might be some in-situ damming still.
Snowing/Sleeting across northern NC at 168
Downeastnc
Member
GFS a little slower but still has the changeover to snow for NC.....gonna be lower on the totals though, more for VA....
LukeBarrette
im north of 90% of people on here so yeah
Meteorology Student
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2017-2023 Supporter
It’s so odd seeing this solution the gfs is printing but then the Euro is printing a full on CAD storm. Lots of differences to work out.